Engineering Physics

5.2 Classical free electron theory of metals

The classical free electron theory was introduced by P. Drude in 1900 and developed by Lorentz in 1909 to explain electrical conduction in metals. This theory has some assumptions; they are:

1. The valence electrons of metallic atoms are free to move in the spaces between ions from one place to another place within the metallic specimen similar to gaseous molecules so that these electrons are called free electron gas. These electrons also participate in electrical conduction; hence they are called conduction electrons.
2. There is no interaction between these conduction electrons.
3. The interaction of free electrons with ion cores is negligible.
4. The free electrons find uniform electric field of positive ions ...